Fordefi vs Fireblocks: choosing infrastructure for DeFi operations

The verdict

For a team whose day is mostly contract calls, Fordefi is the more purpose-built choice. Its approval screen resolves contract names, simulates the outcome, and flags risk, its policy engine can make decisions on simulated values and decoded call parameters, and it documents what happens when a simulation cannot complete. Fireblocks also documents transaction simulation and dApp protection for DeFi, alongside WalletConnect, a browser extension, a DeFi API, whitelisted contracts and approved methods, and contract-call policy rules. Its centre of gravity, though, is custody, exchange connectivity, and treasury across a very large asset list.

Choose Fordefi if DeFi is the core workload and you want simulation to feed policy decisions across a wide set of chains, with explicit failure semantics. Choose Fireblocks if DeFi is one activity among trading, settlement, staking, and tokenization that you want on a single vendor. If your protocol activity is on EVM networks and you want contract-level permissions enforced onchain rather than in a vendor enclave, Den is a third option we cover at the end.

Den publishes this blog. The comparison below uses each vendor's public documentation as read in September 2026.

Two different starting points

Fordefi's founding argument, in its own launch essay, is that wallets designed before modern DeFi cannot protect against DeFi attacks because the signer cannot see what a contract call will do. Everything in the product follows from that: a multi-chain browser extension as the DApp gateway, transaction enrichment and simulation for approvers, and a policy engine that understands contract interactions.

Fireblocks' platform overview frames the product around custody and risk principles: zero counterparty risk, elimination of attack vectors, business continuity, granular control, and performance. DeFi access is one capability among vault accounts, the Fireblocks Network, exchange accounts, and the Gas Station, and its DeFi page packages simulation, dApp protection, and governance rules as a DeFi security suite within that platform.

Neither framing is wrong. They tell you what each vendor optimizes for when a design decision has to be made.

Side by side

What the approver sees

This is the section that should decide the purchase for a DeFi desk.

Fordefi's security documentation describes three things shown before approval: the contract resolved into a verified human-readable name, a simulation showing which tokens will be sent or received and which approvals will be used, and a risk scan that identifies phishing attempts and suspicious interactions. The products page adds that contract metadata and DApp names are verified against known address databases, with alerts for novel interactions.

Fireblocks' DeFi page documents transaction simulation that previews the estimated token balance change when interacting with a smart contract on Ethereum and Solana, dApp Protection that identifies suspicious contracts, phishing websites, and compromised applications in real time, and governance through whitelisted contracts and dApp URLs, approved contract methods, and rules that limit exposure to unknown destinations. Its governance page adds a policy inspector that shows how each transaction was evaluated and a DApp Connection Policy for which applications may connect.

The difference we can evidence is scope and depth of documentation rather than presence or absence. Fordefi documents simulation across its chain families, as an input to policy rules, and with explicit behaviour when it fails. Fireblocks documents simulation for Ethereum and Solana on the page we read. If your protocols live on other chains, ask Fireblocks what the approver sees there, and ask both vendors to demonstrate on your actual protocols.

Policy engines, including the edge cases

Both engines are rule lists with conditions and actions. The differences are in the conditions available and what happens when the inputs are incomplete.

Fordefi's rule conditions include initiator, origin vault, transaction type across transfers, contract calls, allowances, message signatures, black-box signatures, deployments and swaps, recipient by address book or DApp, asset sent, USD amounts per transaction or per period with a choice of outgoing or net value, external screening results from Blockaid or Hypernative, and ABI matching by function and parameter. Actions are allow, block, or require approval. When an amount is unknown, rules with a less-than-or-equal amount condition do not match and rules with a greater-than condition match conservatively.

Fireblocks' policy reference exposes rules with ALLOW, BLOCK, or 2-TIER actions, source and destination scopes, asset, amount in USD, EUR or native units, single-transaction or time-window scope, and transaction types including CONTRACT_CALL, APPROVE, MINT, BURN, STAKE, RAW, and TYPED_MESSAGE, with designated signers and authorization groups. Rules are evaluated first-match, and the rule set is signed by an admin quorum and enforced inside the SGX enclave per the platform overview. The DeFi page adds whitelisting of contracts and dApp URLs and approval of specific contract methods.

The edge case that matters most for DeFi is a failed or skipped simulation. Fordefi documents it plainly. Its simulation API lets programmatic callers skip prediction for latency-sensitive flows, at the cost of policy matching on simulated fields, and lets you decide whether a prediction failure blocks the transaction or falls back to the default rule. The override guide explains that when simulation fails, token and amount are unavailable, rules are matched on the remaining fields, and the default rule applies when a match cannot be determined. Fordefi's advice is to make the default rule strict, for example by requiring multiple approvers. Take that advice. A permissive default rule is the single easiest way to undo everything else in the policy. The Fireblocks pages we read do not describe what its simulation does when it cannot complete, so put that question on the demo agenda.

Automation

Fordefi's API Signer runs in your infrastructure as a container or Kubernetes deployment, holds the first of the two MPC shares, and signs without human intervention when policy allows. The docs limit each organization to one API Signer and recommend blocking all ingress since it needs only egress to Fordefi. The security note is candid: even an attacker with the decrypted share in memory cannot sign without Fordefi's enclave share, and transaction policies still apply.

Fireblocks' API Co-Signer is an enclave application on SGX, AWS Nitro, or GCP Confidential Space that holds the share for signing API users, polls for requests, and can defer to an HTTPS callback handler you write. It is more infrastructure to run and it puts hardware isolation around the automation share. Fireblocks also sells an Automation add-on that rebalances or sweeps assets, tops up balances, and triggers transfers on conditions such as incoming deposits or balance changes, with every rule passing through the Policy Engine.

Fordefi's automation is aimed at a different problem. Its CARE engine with Hexagate lets you pre-record transactions such as withdrawals or approval revocations and have them executed when an onchain trigger fires, for example a protocol exploit or a depeg. If you hold large positions in protocols, that is worth a demo.

Key custody, recovery, and continuity

Fordefi's MPC page describes distributed key generation so that a full key never exists, with the server share inside AWS Nitro secure enclaves. Its backup documentation lists five methods: threshold recovery phrases held by several admins, an air-gapped public key upload, a YubiKey, or third-party escrow through Coincover or Station70. The vendor-stated certifications are SOC 2 Type II audited by Ernst and Young and cryptographic review by NCC Group.

Fireblocks' key material and MPC execution live in SGX enclaves per its platform overview, with hot, warm, and cold configurations that move your share between an API co-signer, a mobile device, or an air-gapped device. Ask Fireblocks to walk through workspace key backup and recovery during diligence. Its support documentation was not accessible for this review, so we do not describe it here.

Which one should you pick?

Pick Fordefi if the following describe your desk: most transactions are contract calls, approvers are not always the people who built the transaction, you want policy that reasons about simulated outcomes and decoded parameters, and you need non-EVM DeFi such as Solana, Cosmos, or Sui. Accept that you are buying a specialist and that payment operations tooling is not its emphasis.

Pick Fireblocks if you need one platform for DeFi and everything else, especially exchange settlement and the Fireblocks Network, or if your institution has already standardized on it. Fireblocks documents simulation on Ethereum and Solana and dApp protection. Verify the chains and protocols you actually use in a demo, and ask how the policy engine treats a transaction when simulation is unavailable.

Where Den fits

Den approaches DeFi controls from the contract side. A Den policy for contract interactions can restrict the contract address, the function, and the argument values, for example allowing only a specific lending pool, only its deposit function, and only when the asset argument is USDC. Argument filters support exact matches, ranges, and address allowlists. The same policy is validated three times: by the SDK or mobile signing client, by the Guardian service, and by the onchain contracts before execution. A compromised server cannot widen the permission because the contract will revert a call that does not match.

That is a different security argument from either vendor above. Fordefi and Fireblocks enforce policy in enclaves they operate. Den enforces it in open-source, audited contracts on the chain itself, in addition to client and server checks. The tradeoff is scope: Den supports EVM networks only, offers a TypeScript SDK, and does not publish balance-change simulation in the approval flow in the way Fordefi and Fireblocks do. Transactions are decoded for review in the dashboard and mobile app. For an EVM protocol desk that wants permissions it can verify onchain, see the DeFi deposit guide and our protocol operations overview.

For the wider field, read Fireblocks alternatives. To understand the account-model question underneath all of this, read Safe vs MPC wallets.